Type-writing and calculating machine.



A. W. HARRIS.

TYPE WRITING AND UALGULATING MACHINE.

APPLIOATION FILED 311.20, 1912.

1,029,500. Patented .nine 11, 1912.

COLUMBIA PLANooRMM c0wAs1uNG'roN, D, c.

sTaTEs PATENT euren;

ARTHUR WILLIAM HARRIS7 OF LONDON, ENGLAND, ASSIGNOR T0 THE HARRIS CAL- CULA'IIN G MACHINE COMPANY LIMITED, 0F LONDON, ENGLAND.

TYPE-WRITING AND CALCULATING MACHINE.

Specification of Letters Patent.

Patented June 11, 1912.

Application filed February 20, 1912. Serial No. 678,897.

To all whom it may concern:

Be it known that I, ARTHUR WILLIAM HARRIS, a subject of the King of Great Britain and Ireland, and residing at Bush Lane I-Iouse, Bush Lane, Cannon street, London, E. C., England, have invented certain new 4and useful Improvements Relating to Type- Writing and Calculating Machines, of which the following is a specification.

This invention relates to typewriting machines having arranged therewith pneumatically operated calculating machines as described, for example, in my former speciiication of Letters Patent No. 995135 and has for its object to provide improved pneumatic mechanism for returning the typewriter carriage to its initial position at the will of the operator.

Reference is to be had to the accompanying drawing which represents a diagrammatical elevation of the invention with parts shown in section.

In one convenient manner of carrying the invention into effect as shown in the accompanying diagram, a comparatively short cylinder a is mounted in any convenient position adjacent to the typewriter carriage, and within the said cylinder are arranged concentric telescopic pistons o, ZJ, b2 and rods c, c o2, the central one (o2) of which is adapted to operate upon the carriage through a lever n. The pistons are held in their innermost position by springs d.

Any convenient valve mechanism may be employed. Preferably the valve comprises a body part e containing a sliding plug f, which when actuated in one direction by a finger key g presses a valve L off its seating and permits air' to be admitted from any convenient pump or reservoir to the cylinder aforesaid. When the linger key is released the valve 7L and plug f are returned by the spring c' and a valve j is opened at the outer end of the plug by a spring lo permitting air to escape to atmosphere from the cylinder along the interior of the plug. Motion is transmitted to the plug from the finger key by a bell crank lever Z which is actuated in one direction by a spring m.

The stroke of each piston is relatively short, but the total movement 'of all the pistons is suflicient to return the carriage from one limit of its movement to the other. In the arrangement shown the abutment on the Vtypewriter carriage is in the form of a lever n pivoted on the sliding carriage which supports the usual roller and connected by a link 0 with a lever p by which an ordinary ratchet device is operated for producing the usual partial rotation or angular movement of the roller whereby the paper is advanced to a new position after a line has been completed. The first action of the central piston is to move the lever n sufhciently to actuate the ratchet device. At this position the lever is arrested and further movement of the piston is transmitted through the lever to the carriage.

For putting the piston out of action when the carriage reaches its initial position a trip piece g suitably situated near the carriage is connected by rods r and bell crank lever s with the catch t bywhich the finger key aforesaid is held down after depression, such holding down being effected by the engagement of the catch with a collar a on the stem of the key. As the carriage reaches its initial position, a projection o thereon operates the trip piece and liberates the catch and finger key and permits the valve 71, to close under the action of the spring and air to be released from the cylinder through the valve The catch and trip aforesaid are held in or returned to their operative position after displacement therefrom by any suitably arranged spring (not shown). In the position of the mechanism illustrated by the diagram the carriage lis dsupposed to be moving toward the cylm er.

To prevent undue impact of the carriage against its stop when returned by mechanism as above described, the piston may be arranged to be put out of action before the carriage completes its return movement, the completion of such movement being eifected under momentum. For this purpose the projection fo may be arranged to liberate the valve before the carriage reaches the end of its movement. The projection is preferably adjustably mounted on a rack bar fw secured to the carriage. Another method of reducing the impact of the carriage against the stop at its initial position, consists in so proportioning the springs controlling the concentric pistons above referred to that the pressure applied to the carriage by the pistons progressively diminishes as the carriage approaches the stop. It must be observed that this condition is inherent in the arrangement of pistons shown in the drawing, but by suitably proportioning the springs the progressive reduction of pres-A sure can beincreased.

The invention 1s not limited to any particular cylinder or valve mechanism, or

means for producing or controlling tlieYM movement of the carriage, as these details may be varied to suit diifer'ent requirements. Having noW particularly described and ascertained the nature of my said invention a pneumatic cylinder, valve and finger key,

of a'collar and valve lever in conjunction With the key, a catcli adapted to engage the collar When the key is depressed, a trip piece adjacent the carriage, a projection on the carriage for actua-ting` said piece, and rods and bell crank lever connecting the catch and trip piece, substantially as described.

In testimony whereof, I aiilx my signature in prese-nce of tWo Witnesses.

ARTHUR WILLIAM HARRIS.

Vitnesses:

JOHN MORGAN, GWYNNE MORGAN.

Copies of this patent may be obtained'for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

